Infections of the Nervous System I A Lecture Outline © Hanuš Rozsypal
	Meningism | Lumbar puncture | CSF examination | Bacterial meningitis

• central nervous system
  • meningitis
  • encephalitis
  • myelitis
• peripheral nervous system
  • radiculitis
  • neuritis
• combined involvement
  • meningoencephalitis
  • encephalomyelitis
  • polyradiculoneuritis

• purulent
• aseptic
• specific

• acute
• subacute
• chronic

• inflammation
• hemorrhage
• neoplasm
• increased intracranial pressure, high temperature etc.

• headache
• vomiting
• irritability, hyperesthesia, photophobia etc.

• meningeal signs

• To obtain CSF in a suspicion of meningitis
• Reduction of raised intracranial pressure
• Lumbar intrathecal instillation of drugs

1. Mass lesion or very increased intracranial pressure (possible danger of herniation - tentorial or cerebellar coning) Some evidence for this circumstance are
   • rapidly developing depression of consciosness (coma)
   • focal neurologic signs
   • convulsions
   • papilledema.
2. Significant coagulopathy (possible danger of bleeding)
3. Infected lumbar area (possible danger of infection)

• Cytology
  • cell count

• Chemistry
  • protein
  • glucose
  • chloride

• Microbiology:
  • Gram´s staining
  • latex agglutination
  • bacterial cultures

• Serologic tests:
  • Lyme disease serology

• Cytology:
  • smear of the sediment
  • immunocytology
• Chemistry:
  • lactic acid
  • colloidal gold curve
  • oligoclonal bands
  • immunoglobulins
• Microbiology:
  • india ink
  • fungal cultures
  • mycobacterial studies
  • electron microscopy (Borrelia burgdorferi)
• Virology:
  • viral cultures
  • PCR
  • electron microscopy (JCV)
• Serologic tests:
  • syphilis serology

• Cell count: normal or low lymphocytar pleocytosis (<50/3ml)
• Protein: high (usually about 1g/l)
• Glucose: normal
• Chloride: normal

• Cell count: low mixed pleocytosis
• Protein: high
• Glucose: low
• Chloride: low

• Cell count: low mixed or polymorphonuclear pleocytosis
• Protein: high
• Glucose: normal
• Chloride: normal

  Major causative organisms (90%)

• Streptococcus pneumoniae (pneumococcus)
• Neisseria meningitidis (meningococcus)
• Haemophilus influenzae

  routes of infection

• hematogenous
• per continuitatem
• direct invasion (penetrating head trauma, meningomyelocele)

1. Primary
2. Secundary
   • pneumonia (pneumococcus)
   • head trauma - penetrating or closed (pneumococcus, staphylococcus, G- bacilli)
   • chronic otitis media (pneumococcus)
   • sinusitis (pneumococcus, Haemophilus)
   • neurosurgery (G- bacilli, staphylococcus, anaerobes, Nocardia)
   • CSF shunt (Staphylococcus epidermidis, S. aureus, G- bacilli, diphteroids)

• rapid onset
• fever
• headache
• vomiting
• confusion
• others: seizures, skin rash, myalgias

• fever
• meningismus
• skin rash (petechiae)
• other neurologic and related findings
  • altered consciousness
  • cranial nerve palsies
  • signs of increased intracranial pressure (HR, BP, breathing, cranial nerves involvement)
  • focal neurologic signs (hemiparesis, aphasia)
• other complaints
  • herpes labialis
  • signs of shock

• ESR: very high
• BC: leucocytosis
• CRP: very high
• CSF: polymorphonuclear pleocytosis, high protein level, hypoglycorrhachia

• cerebral abscess
• subdural and epidural empyema
• thrombophlebitis of venous sinus
• subdural effusion (hygroma subdurale)
• obstructive hydrocephalus

Purulent Meningitis (Normal CT Scan)	Cerebral Abscess *
Epidural Empyema *	Subdural Effusion **
Obstructive Hydrocephalus	Pneumocephalus

• cranial nerve palsies
• motoric involvement (for example hemi- or quadruparesis, ataxia)

• myocarditis
• pericarditis
• metastatic or reactive arthritis
• disseminated intravascular coagulopathy (DIC)
• Watterhouse-Friderichsen´s syndrome

• pneumonia
• urinary tract infections (UTI)
• intravenous catheter-related bacteremia or sepsis
• fever (>4 days)

• behavioral disturbances, mental retardation
• visual problems
• hearing loss (deafness)
• motoric involvement (permanent paralysis)
• secundar epilepsy

• History: chronic otitis media and head trauma.
• Symptoms and signs: fever, headache, meningism and signs of cerebral dysfunction (declining level of consciousness).
• Laboratory data: CSF - pyogenic formula, ESR, BC, CRP - consistent with bacterial infection
• Additional examinations:
  • Hemocoagulation
  • Chemistry
  • Blood cultures
  • Fundoscopy (because excluding of papilledema)
  • ENT exam
  • X-ray (of chest, skull, mastoids, sinuses)
  • CT scans, MRI, brain ultrasonography (in infancy)
  • Audiogram
  • Radioisotopic scanning

• Non-bacterial meningitis (aseptic, tuberculous, fungal)
• Brain abscess
• Intracranial or spinal epidural abscess/ empyema
• Subdural empyema
• Bacterial endocarditis with embolism
• Thrombophlebitis of venous sinus
• Ruptured dermoid cysts
• Brain tumors

• the causative microorganism
• the age of the patient
• the underlying diseases

1. Antimicrobial agents:

2. Reduction of intracranial pressure:
   • Mannitol 20% (0.25g/kg q4-6h IV = 1.0-1.5ml/kg q4-6h IV)
   • Dexamethasone (0.15mg/kg q4-6h IV)
   • (Hyperventilation)

3. Other supportive care and symptom-based therapy
   • Infusions
   • Antipyretics
   • Anticonvulsants
   • Mechanical ventilation

4. Treatment of complications

• H. influenzae: H. influenzae type b (Hib) conjugate vaccine
• N. meningitidis: quadrivalent meningococcal vaccine (active against serogroups A, C, Y, and W135)
• S. pneumoniae: 23-valent pneumococcal vaccine
• S. agalactiae: not possible
• Basilar skull fracture: 23-valent pneumococcal vaccine (?)

• H. influenzae: (rifampicin)
• N. meningitidis: penicillin, co-trimoxazole, macrolids, rifampicin, ceftriaxone, ciprofloxacin
• S. pneumoniae: (penicillin, rifampicin)
• S. agalactiae: (ampicillin or penicillin intra partum)
• Basilar skull fracture: not recommended (?)